M42 engine info needed please
 

Hi Guys,

I would like to know if the e30 318is M42 engine and the 95 318ti M42 engines are the same?

I know that the crank pullies are different, the e30 has a V belt and the ti uses a serpentine belt. Can the pullies be inerchanged? I also noted that the intake is different. Are all the major components the same, like cams, block, head, etc? Would the tranny from an e30 318is bolt up to the 318ti m42 engine?
Can the e30 m42 be directly dropped into the 318ti?

Many thanks for reading.

Ralph.

the e30 gearbox should bolt up, but the gear ratios will be wrong for a stock 5 speed ti diff. The 5th gear ratio is closer to .8:1 instead of 1:1.

The engine internals are the same, the computer systems are different IIRC. You could swap the manifolds/accessories and probably make it work in the ti, it'd be an extra few hours of work.

Hi Andy,

Thanks for the reply. I dont mind swapping manifolds etc over as I will have to rebuild this motor anyway before swapping it.

The car has an auto right now and I am looking into doing a manual swap using the e30 318is 5 speed tranny. I will install a 3.73 LSD from the e30 325is into the 95 ti as well.

Would you know how difficult it is to do an auto to manual tranny swap?
On the e30's it's not too difficult, but not sure about the e36 ti.

Thanks,

Ralph.

Disregard tranny swap info request please, just found an interesting thread http://www.318ti.org/forum/showthread.php?t=11318

the 3.73 diff will be too low for the e30 318i tranny. Stock those cars came with a 4.10 diff. With that setup the revs will be 15% lower than a stock 5 speed ti. You'd be a lot closer to stock ti specs if you left the stock auto diff in place. The whole reason for this is that the gears are a lot taller in the e30 transmissions and 5th gear is close to .8:1 ratio and our e36's are 1:1.

if you're rebuilding the motor anyway, why not just rebuild your ti motor?

I'm not sure about the e30 transmission in the 318i that you have access to, but I've had issues with 2 different output flange sizes. This usually isn't a problem with those cars since you can swap the driveshafts between the 2, but in your case you'll want the small output shaft flange to mate with a 5 speed ti driveshaft. Also, you may have to custom fit shifter brackets too. I'm trying to think of all the hang ups of putting an e36 drivetrain in an e30, your problems will be the opposite of those... you can get info on that here http://www.akgmotorsport.com/usm50swap.html

Keep in mind pre '93 M42 engines also have 7mm valve stems. 93-95 have 6mm

That makes sense Andy, I will leave the ti's diff as is.


I would like to turbocharge the ti, it would be easier to rebuild a spare motor and do all the custom fab with the motor out of the car and will prevent the car from being out of commission for too long as well.
Having the original motor in the car while doing the turbo charging project on another motor will allow me to make measurements, do cross references etc.

Many thanks Andy for the info and the link.

BTW, I have just installed a Koni/H&R lowering kit on the ti and cant believe how well the car handles, how it still maintains a great ride comfort and looks great all at the same time



Regards,

Ralph.

Thanks Dave.